July 14, 2017

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6th-grader invents water-testing device that could help get the lead out

by John_A

Why it matters to you

Eleven-year-old Gitanjali Rao is one of just 10 finalists for the Discovery Education 3M Young Scientist Challenge, and her invention just might save lives in the future.

“My name is Gitanjali Rao and I like finding solutions to real problems,” says the 11-year-old girl finalist in one of the most distinguished science competitions in the U.S. Her invention, a sophisticated method for testing for lead contamination in water, could significantly improve the response to chemical disasters like the water crisis in Flint, Michigan. In fact, Rao’s water-testing device was partially inspired by stories of chemical contamination like the situation in Flint.

“Imagine living day in and day out drinking contaminated water with dangerous substances like lead,” Rao explains in her entry. “Millions of people around the world are exposed to water containing lead and its harmful side effects. There are over 5,000 water systems in the U.S. alone with lead contamination issues. Timely detection and preventative action can help mitigate the problem, but today it takes a long time because of chemical labs and expensive equipment. My solution addresses a core issue of speedy detection of lead contamination, allowing preventative action and even saving lives!”

Rao is a student at Brentwood Middle School in Brentwood, Tennessee, and one of 10 finalists in the 2017 Discovery Education 3M Young Scientist Challenge. It’s a one-of-a-kind video competition aimed at sparking the imaginations of students across the country.

Her enthusiasm is infectious, and her solution is positively radical. In reading through materials on the Massachusetts Institute of Technology’s material science department website (as typical sixth-graders are not known to do), Rao learned about a new type of nanotechnology — and made the correlative leap to recognize a new practical application for it.

Her test device, which she has dubbed “Tethys,” uses a disposable cartridge containing chemically treated carbon nanotube arrays. This connects with an Arduino technology-based signal processor with a Bluetooth attachment. The graphene within the nanotube is highly sensitive to changes in flow of current. By treating the tube with atoms that are sensitive to lead, Rao is able to measure whether potable water is contaminated with lead, beaming the results straight to a Bluetooth-enabled smartphone. When it detects levels higher than 15 parts per million, the device warns that the water is unsafe.

Even the name of the device is clever — in Greek mythology, “Tethys” is the Titan daughter of Uranus (Earth) and Gaius (Sky), and the mother of river gods.

Rao’s Tethys device offers real innovation in allowing live testing for chemical contaminants. Homeowners currently have to ship a kit to a chemical lab and wait a week or more for results. Most of the testing device is reusable, meaning it could potentially be produced at mass-market costs. Rao estimates that a Tethys kit could potentially cost as little as $20 or less. She’s working with a mentor at 3M to explore developing a product that people can buy.

“Clean water always makes you feel good,” she says. “The tool allows easy testing at home and by agencies for quick detection and remedial actions. It can be expanded in the future to test for other chemical contaminants in potable water.”

Tethys isn’t even Rao’s first invention. She was the first girl in Middle Tennessee to earn the designation of STEM Scout of the Year from the Boy Scouts of America — Middle Tennessee Council for inventing a device that can determine the kind and amount of toxin in a snakebite. She also placed third in the EngineerGirl Essay Contest with her essay, “Saving Mountain Gorillas with Machine Learning and Predictive Analytics,” and she’s won the National Association of State Aviation Officials Tennessee Art Contest three years running.

In October, Rao will travel to the 3M headquarters in Maplewood, Minnesota, where she’ll compete against the other finalists for a grand prize of $25,000 and the title of “America’s Top Young Scientist.” In future years, she hopes to become a geneticist or an epidemiologist, working in the field of disease theory.

On the Discovery Education 3M Young Scientist Challenge website, Rao offers advice for other kids. “Just have fun,” she says. “There’s never a limit to how many times you want to keep trying and tweaking your projects. Keep trying, and one day, you’ll figure it out.”